Bump postcss from 8.4.8 to 8.4.12 (#16949)

Bumps [postcss](https://github.com/postcss/postcss) from 8.4.8 to 8.4.12.
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss/compare/8.4.8...8.4.12)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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package.json

@@ -132,7 +132,7 @@
     "intersection-observer": "^0.12.0",
     "linkstate": "^2.0.1",
     "lodash.debounce": "4.0.8",
-    "postcss": "^8.4.8",
+    "postcss": "^8.4.12",
     "postcss-cli": "^9.1.0",
     "postcss-cssnext": "^3.1.0",
     "postcss-smart-import": "^0.7.6",

yarn.lock

@@ -13379,10 +13379,10 @@ postcss@^7.0.0, postcss@^7.0.1, postcss@^7.0.14, postcss@^7.0.17, postcss@^7.0.2
     picocolors "^0.2.1"
     source-map "^0.6.1"
 
-postcss@^8.2.15, postcss@^8.4.8:
-  version "8.4.8"
-  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.8.tgz#dad963a76e82c081a0657d3a2f3602ce10c2e032"
-  integrity sha512-2tXEqGxrjvAO6U+CJzDL2Fk2kPHTv1jQsYkSoMeOis2SsYaXRO2COxTdQp99cYvif9JTXaAk9lYGc3VhJt7JPQ==
+postcss@^8.2.15, postcss@^8.4.12:
+  version "8.4.12"
+  resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.4.12.tgz#1e7de78733b28970fa4743f7da6f3763648b1905"
+  integrity sha512-lg6eITwYe9v6Hr5CncVbK70SoioNQIq81nsaG86ev5hAidQvmOeETBqs7jm43K2F5/Ley3ytDtriImV6TpNiSg==
   dependencies:
     nanoid "^3.3.1"
     picocolors "^1.0.0"